Effect of Smoking Method on Quality Attributes of Traditional Smoked Silver Catfish (Chrysichthys Nigrodigitatus) from Lagos State, Nigeria

Abstract

Effect of smoking methods on quality and safety of traditional smoked silver catfish from Lagos State, Nigeria was carried out with a focus on investigating the quality indices of traditional smoked silver catfish in twenty different fish processing centres.  Fresh unsmoked silver catfish and smoked silver catfish samples were collected from different processing centres and and control samples were smoked with convectional smoke kiln. Proximate and quality analyses revealed that moisture content of fresh unsmoked silver catfish samples ranged from 71.66% – 74.92% and that of smoked silver catfish samples and control samples ranged from 11.18% - 14.77% and 8.48% – 10.43% respectively. Protein content of fresh unsmoked silver catfish samples ranged from 15.70% – 17.96% and that of smoked silver catfish samples and control samples ranged from 52.96% – 58.36% and 56.81% – 61.42%. Fat content of fresh unsmoked silver catfish samples ranged from 7.58% – 9.86% and that of smoked silver catfish samples and control samples ranged from 16.52% – 20.41% and 17.52% – 20.57%. The pH value of fresh unsmoked silver catfish samples ranged from 6.78 – 7.42 and that of smoked silver catfish samples and control samples ranged from 6.27 – 6.73 and 6.51 – 6.86. The TBA values of fresh unsmoked silver catfish samples ranged from 0.90 - 1.18mgMol/kg and that of smoked silver catfish samples and control samples ranged from 1.01 - 1.15mgMol/kg and 1.00 – 1.12 mgMol/kg. The TVB-N of fresh unsmoked silver catfish samples ranged from 13.15 - 15.40mgN/kg and that of smoked silver catfish samples and control samples ranged from 17.59 - 19.69mgN/kg and 15.63 - 17.86mgN/kg. The TMA of fresh unsmoked silver catfish samples was 2.04 – 2.61mgN/kg and 2.36 – 2.96mgN/kg and 2.11 – 2.72mgN/kg for smoked silver catfish samples. This study revealed PV of 6.13 – 8.85 mgEq.peroxide/kg for fresh unsmoked silver catfish samples and 8.24 - 9.39mgEq.peroxide/kg and 7.13 - 8.67mgEq.peroxide/kg for smoked silver catfish samples. FFA of fresh unsmoked silver catfish samples was 1.00 – 1.16% while that of smoked silver catfish samples ranged from 1.03 – 1.26% and 1.00 – 1.24%. Convention smoke kiln (used for control samples) did not significantly affect pH and composition of smoked silver catfish. The study concluded that smoking method affect quality as convention smoke kiln significantly reduced the moisture content of smoked silver catfish and the quality indices such as FFA, TBA and PV.

Keywords: silver catfish, smoking, traditional, quality, smoking method